Modeling and vehicle performance analysis of Earth and lunar hoppers

Abstract

Planetary hoppers-vehicles which travel over the surface as opposed to on it-offer significant advantages over existing rovers. Above all, they are able to travel quickly and can overcome terrain obstacles such as boulders and craters. The Next Giant Leap team in the Google Lunar X- PRIZE competition plans on utilizing hopper technology for its design, but they have little from which to work. In fact, although hopper-like vehicles have been created and flown, none have been used to serve specifically as tools for planetary exploration. Thus it is clear that prototyping and modeling will have to be done in order to gauge the feasibility of such a system. To support this effort, this thesis provides a look into the performance of hopper technologies through modeling and simulation. It begins by using the Hop Tradespace Tool to examine the two fundamental hop trajectories, determining that although there is a fuel savings with the ballistic hop, the hover hop is more desiresable for testing. This result is then applied to a preliminary mission analysis for the TALARIS prototype vehicle. Finally, the Earth TALARIS and its lunar version are modeled in 3-DOF simulation and it is discovered that, even with error and uncertainty, TALARIS closely emulates what would be expected to be seen on the Moon.